1. Field of the Invention
The present invention relates to an apparatus for effecting gas-tight communication between first and second members having bores for the passage of fluid. More particularly, the present invention relates to a high-temperatures, low-pressure connection for effecting fluid-tight communication between such members.
2. Description of the Background
There are numerous types of apparatus such as, for example, analytical instrumentation used in laboratories, chemical and refining plants and the like, which require connection of a first member through which is transported a fluid, such as a gas, to a second member, through which is transported the gas. In many cases, the connection is subject to extended, high temperatures, followed by periods of much cooler, even subfreezing temperature. The components of mechanical connections placed in this environment, because of the temperature swings, are subject to expansion and contraction with the result that eventually the connection is no longer gas-tight. For example, in the field of chemical analysis by pyrolysis or thermal degradation, extremely high temperatures are generally employed. Not only are such temperatures employed in the actual pyrolysis of the sample to be analyzed, but in the subsequent analysis of the thermally evolved products, it is generally necessary to maintain the temperature of the flow lines through which the evolved products flow at a high temperature in order to avoid their condensation prior to being sent to a suitable analyzer. Frequently in these systems, gas chromatographic analyzers are employed, and the flow lines and connectors are subject to these high temperatures and temperature swings.